Various engraved plates for forming a fine pattern such as a color filter used in a color liquid crystal display apparatus, for gravure printing, for coating of an adhesive compound, and for transfer coating of a resist material are conventionally used.
Patent Documents 1 and 2 disclose a method of manufacturing an engraved plate. In this method, a metal which is easily etched is plated on a metal roll-like or plate-like substrate, a photosensitive resin is coated to an upper surface of the resultant structure, a direct latent image is formed by exposure, and a resin on an unnecessary portion is removed to form an etching resist pattern. The metal is etched, and the resin is stripped. Furthermore, the documents disclose that nickel electroplating or chromium electroplating is performed on a surface of the engraved plate to improve the plate life.
However, the manufacturing method includes a large number of steps. Since the method has an etching step, depending on cases, further has a chromium electroplating step, an accurate shape cannot be easily given, and a uniform shape of a recessed portion, linearity of a concave portion edge and accuracy of a concave portion thickness cannot be easily obtained.
In recent years, as a substitute of chromium electroplating performed after etching, a silicon oxide layer, a titanium nitride layer, or a diamond-like carbon (to be referred to as DLC hereinafter) layer serving as an inorganic material is used. However, as in a conventional method, an etching step which cannot easily give an accurate shape is required.
Patent Document 3 discloses an electromagnetic wave shielding plate including, as an electromagnetic wave shield layer, a metal mesh formed by using an engraved plate. The electromagnetic wave shielding plate is manufactured such that a metal is electrodeposited with a metal electrolytic solution on an electrodeposition substrate on which a mesh-like metal can be electrodeposited, and the mesh-like metal is bonded to and transferred to a substrate for the electromagnetic wave shielding plate through a bonding agent. In the document, the electrodeposition substrate may be manufactured as follows. The document discloses that an inverted pattern of a mesh pattern is formed on a conductive substrate such as a metal plate by an insulating film which blocks electrodeposition, and an electrodeposition portion on which metal electrodeposition can be performed in the form of a mesh is exposed. The document discloses that the electrodeposition substrate is manufactured by forming a convex conductive mesh layer on an insulating layer support member.
Patent Document 3 discloses that, in manufacturing of the electrodeposition substrate, an insulating layer is formed with a photoresist. When such electrodeposition substrate is used, the electrodeposition substrate can be repeatedly used several times or about several tens of times, however, the electrodeposition substrate cannot be used several hundred times to several thousand times, and the electrodeposition substrate is insufficient to mass-product an electromagnetic wave shielding plate. This is because an insulating layer forming a mesh pattern on the electrodeposition substrate suffers peeling stress by adhesion and transfer, and the insulating layer is peeled from the conductive substrate by several repeated uses.
Patent Document 3 discloses an electrodeposition substrate in which SiO2 is formed on a conductive substrate and photoetched to form an insulating film. However, since the photoetching step is performed, the number of steps in manufacturing the electrodeposition substrate increases. Overetching makes a concave portion narrow toward the opening of the concave portion.
Patent Document 3 discloses a method of forming a necessary concave portion by photolithography or carving on a metal substrate surface, burying and curing a strong insulating resin in the concave portion, and curing the insulating resin to manufacture an electrodeposition substrate having an electrodeposition portion on which a metal can be electrodeposited in the shape of a mesh. However, when the concave portion is formed in the metal substrate by this method, the method does not produce sufficient results in pattern accuracy, a defect-free pattern and required time for pattern manufacturing. When an insulating resin is used in an insulating layer, the endurance (durability) of the insulating layer is not sufficient.
Patent Document 3 discloses that, when a single metal plate consists of tantalum, titanium, or the like or the surface is a metal surface consisting of the material, after a resist is formed on only a corresponding to a portion constituting the electrodeposition portion, anodization is performed to form an insulating oxide layer consisting of titanium oxide, tantalum oxide, or the like, and the resist is removed, and a resultant electrodeposition substrate has an excellent effect. However in cross section of the electrodeposition substrate, the mesh pattern of concave portion (electrodeposition portion) and the insulating oxide layer are substantially flush and do not substantially uneven, since the insulating oxide layer is very thin, and therefore the concave portion can not determine a shape of a electrodeposition layer. More specifically, a line shape to be electrodeposited is not easily controlled. The insulating oxide layer obtained by anodization is deteriorated in endurance, and the insulating oxide layer is not actually suitable for continuous operations. In fact, in electroforming of Ni, anodization is forced to be performed before transfer. Furthermore, since the insulating oxide layer obtained by the anodization has poor insulation performance, the insulating oxide layer is not suitable for high-speed electrolytic plating. However, when the insulating oxide layer is obtained by anodization of aluminum, relatively high insulating performance can be obtained. However, mechanical endurance is deteriorated.
Patent Document 3 discloses a method using a electrodeposition substrate in which a convex conductive mesh layer is formed on an insulating layer support member. According to this method, in fact, a metal is electrodeposited on a side surface of the conductive mesh to form a resistor to adhesion and transfer of the mesh-like electrodeposition metal layer, and the metal layer cannot be peeled. Even though the metal layer can be peeled, the mesh pattern is bent and broken, and electromagnetic wave shielding property is deteriorated.
Patent Document 4 discloses a base sheet for metal layer transfer used to manufacture a circuit pattern of an electronic part and an electrode pattern of a ceramic capacitor. The base sheet for metal layer transfer includes a base metal layer and an electric insulating layer. A convex pattern to form a transfer metal layer by electrolytic plating is formed on the surface of the base metal layer. The electric insulating layer is formed on a portion on which the convex pattern is not formed on the surface of the base metal layer. According to Patent Document 4, a method of manufacturing a base sheet for metal layer transfer is disclosed. In this method, on the surface of the base metal layer, an etching resist is formed by the same pattern as that of the convex pattern by using a dry film resist or the like, and a surface of the base metal layer exposed without being covered with the etching resist is etched to form a concave portion. Thereafter, the etching resist is removed, an electric insulating layer is formed on the entire surface of the etched base metal layer, and the electric insulating layer is polished until the convex pattern is exposed. According to this method, the surface of the electric insulating layer and the surface of the convex pattern of the base metal layer are arranged on the same plane to obtain a flush surface. Patent Document 4 discloses, as another example of the manufacturing method, a method of forming an electric insulating layer consisting of a plating resist on a surface of a base metal layer with an inverted pattern of a convex pattern by using a dry film resist or the like and forming an electrolytic plating metal layer by a convex pattern on the surface of the base metal layer exposed between the electric insulating layers. In this method, the thickness of the electrolytic plating metal layer is made larger than the electric insulating layer. When the surface of the electrolytic plating metal layer is formed at a level higher than that of the surface of the electric insulating layer, in a transfer state of a transfer metal layer formed on the convex pattern by electrolytic plating to an adhesive sheet, the electric insulating layer can be prevented from damaging the adhesive sheet as disclosed in Patent Document 4.
In the Patent Document 4, as a material of the electric insulating layer, an organic insulating resin is disclosed. However, when the transfer metal layer, which is formed on the convex pattern by using the base sheet for metal layer transfer in which the surface of the electric insulating layer and the surface of the convex pattern of the base metal layer are arranged on the same plane to form a flush surface, is transferred to an adhesive sheet, the electric insulating layer on the electrodeposition substrate suffers peeling stress by adhesion and transfer, and the electric insulating layer is peeled from the electrodeposition substrate by several repeated uses.
Patent Document 4 discloses that a transfer metal layer, which formed on a convex pattern by using a base sheet for metal layer transfer in which a surface of the convex pattern constituted by an electrolytic plating metal layer is formed at a level higher than that of a surface of an electric insulating layer, is transferred to an adhesive sheet. However, in this case, the transfer metal layer is plated on a side surface of the convex pattern to form a resistor to adhesion and transfer of the transfermetal layer, and the transfermetal layer cannot be peeled from the convex pattern. Even though the metal layer can be peeled, the mesh pattern is bent and broken, and electromagnetic wave shielding property is deteriorated.
In Patent Document 4, when a method of manufacturing a base sheet for metal layer transfer includes forming of an etching resist on the surface of the base metal layer and etching of the surface of the base metal layer exposed without covered with the etching resist, the number of steps increases, and the productivity is poor.
More specifically, an engraved plate having a uniform-shaped concave portion, a linear edge, high accuracy in depth, and excellent endurance is desired in the past. A method of manufacturing a substrate with conductor layer pattern which is patterned to have electric conductivity and optical transparency by using a transfer method with good productivity is required. Furthermore, an engraved plate for plating which can be easily manufactured is required.    Patent Document 1: JP-A-2006-231668    Patent Document 2: JP-A-2001-232747    Patent Document 3: JP-A-11-26980    Patent document 4: JP-A-2004-186416